1. Towards a general model of action and time;Allen;Artificial Intelligence,1984
2. Allen, J. and Koomen, J., 1983. Planning using a temporal world model. In Proceedings of IJCAI-83, Karlsruhe, West Germany. San Mateo: Morgan Kaufmann Publishers.
3. Natural language input for a computer problem-solving system;Bobrow,1968
4. A model-driven question-answering system for mixed-initiative computer-assisted instruction;Brown;IEEE Transactions on Systems, Man, and Cybernetics,1973